Barnaby Roberts

RESEARCH
A reduction of phosphorus input has changed Lake Constance from a eutrophic environment back to its natural oligotrophic state. As the amount of phosphorus into the lake has reduced so have the yields of many commercially important fish species in the lake. In particular yields of the beloved whitefish or “Felchen” (Coregonus spp.) are greatly reduced.

Felchen are a highly valuable economic and cultural good. Which have been harvested in the lake, in a fishery focused on sustainability and international cooperation, since the Medieval Period. Recently the population of Felchen is decreasing so drastically that reoligotrophication alone cannot explain the change. One possible explanation is a subject that cannot be ignored in the modern age: climate change.  

The impact of climate on the Felchen population in Lake Constance will be the main focus of my research. I will explore the possibility of a trophic mismatch between Felchen larvae and their prey. Hatching time and development of Felchen larvae is highly temperature dependent. Abundance of the organisms they prey upon can also be determined by temperature. Prey species may adapt to changes in water temperatures faster than Felchen are able to. As a result the growing Felchen larvae may not be able to feed on the same prey species, or the same amount of prey, that they did in the past. A reduction in larval Felchen survival caused by such a phenological mismatch could result in low recruitment into the juvenile and eventually adult population.

EDUCATION
2020: Doctorate at University of Konstanz (working at Fisheries Research Station in Langenargen)

Project title: “Reproduction and first feeding of whitefish - highly influenced by climate change?”

2018-2019: MSc Palaeobiology at Univeristy of Bristol

Thesis project:  “How do Milankovitch cycles influence the size of Foraminifera?”

2015-2018: BSc Marine Vertebrate Zoology at Bangor University

Dissertation project: “Depth distribution of coral reef fish”